1. Field of the Invention
The present invention relates to a liquid delivering apparatus and, in particular, to such a liquid delivering apparatus employing a sheet-stacked body in which a piezoelectric sheet and a restrictor sheet are stacked on each other and which is deformed or curved in a direction to increase a volume of a liquid chamber which accommodates a liquid.
2. Related Art Statement
There has conventionally been known a liquid delivering apparatus which delivers a liquid from a liquid chamber to an external location, by deforming a piezoelectric element and thereby applying a pressure to the liquid in the liquid chamber to which the piezoelectric element is opposed. An example of the liquid delivering apparatus is an ink jet recording head disclosed by, e.g., Japanese Patent Application Publication No. 11-34341. The ink jet recording head includes a cavity sheet having a plurality of groove-like ink chambers that communicate with a plurality of ink ejection nozzles, respectively; and a piezoelectric element which is stacked on the cavity sheet so as to close the ink chambers. The piezoelectric element includes an elastic sheet located on the side of the ink chambers; and a piezoelectric sheet stacked on the elastic sheet. The piezoelectric sheet is sandwiched by a single common electrode located on the side of the elastic sheet, and a plurality of individual electrodes located on the opposite side (i.e., on an upper surface of the piezoelectric sheet) and corresponding to the ink chambers. An electric voltage is applied to the common electrode and an arbitrary one of the individual electrodes.
In the ink jet recording head constructed as described above, when a drive device applies a positive voltage to a desired one of the individual electrodes and a negative voltage to the common electrode, a portion of the piezoelectric sheet that corresponds to the one individual electrode is shrunk in directions parallel to opposite major surfaces of the piezoelectric sheet, and a portion of the elastic sheet that corresponds to the one individual electrode restricts the shrinkage of the piezoelectric sheet. Consequently the respective portions of the piezoelectric sheet and the elastic sheet are so deformed or curved as to project into a corresponding one of the ink chambers. This deformation applies a pressure to the ink accommodated in the one ink chamber, and accordingly a droplet of ink is ejected from a corresponding one of the ink ejection nozzles in a so-called “fill-after-fire” manner.